Another idea is a crossover with the Attack on Titan universe. Allen's skills as an Exorcist could be very useful against the Titans. He might be part of a special unit that combines the Survey Corps' knowledge of the Titans with his own abilities to fight off the Titans and any Akumas that might show up in that world.
A crossover with the world of Fullmetal Alchemist would also be cool. Allen could meet the Elric brothers. His Exorcist abilities might be seen as a form of alchemy by some in that world. They could all work together to uncover a conspiracy that involves both the Homunculi and the Millennium Earl.
One plot idea could be a story where Tyki Mikk and Allen Walker are forced to team up against a common enemy greater than their differences. Maybe a new, extremely powerful Akuma that threatens to destroy both the Order and the Noah's side. This would put them in a situation where they have to rely on each other's unique abilities.
First, choose the world you want to crossover with. For example, if it's the Bleach universe, research the rules and characters of Bleach. Then, think about how Allen Walker would fit into that world. What would his role be? After that, create an interesting plot. Maybe Allen has to help Ichigo defeat a new kind of enemy that has the powers of both Hollows and Akumas.
One plot idea could be that the chibi Allen Walker discovers a hidden power within himself while on a simple mission. Maybe he stumbles upon a mysterious artifact that unlocks a new form of his Innocence. Another idea is that he gets transported to a parallel world where everything is in miniature like him, but there are different rules and he has to figure out how to get back. And also, a plot where he befriends a group of other chibi exorcists and they form a special team to take on a powerful Akuma that no one else could defeat.
One great 'Cold Allen Walker Fanfic' could be 'Frosty Encounters'. It really delves into Allen's cold side in a unique way. The author describes his aloofness and how it affects his relationships within the story. Another good one might be 'The Icy Path of Allen Walker' which focuses on his journey while maintaining that cold exterior.
One possibility could be that in the fanfic, Allen Walker's journey to becoming a general is filled with intense battles and self - discovery. He might face numerous challenges that test his strength and resolve, both physically and mentally. His past experiences as an Exorcist could play a crucial role in shaping his path to generalship, perhaps giving him unique insights that others lack.
Well, a possible plot for a Tyki Mikk x Allen Walker fanfiction could involve a situation where Tyki is injured and Allen has to take care of him. This could lead to a lot of tense moments as Allen is not sure if he can trust Tyki, but at the same time, he can't just let him die. Also, a plot could revolve around them being captured by a common enemy and having to work together to escape. Or perhaps a story where they both get transported to a different dimension and have to rely on each other to find their way back while also dealing with their own personal demons.
One main theme is the struggle between good and evil. Since Allen is on the side of the exorcists and the Noah are often seen as antagonists, the fanfics often explore this moral divide. For example, some fanfics might show a Noah having some good qualities, blurring the line between the two sides.
For a 'Cold Allen Walker Fanfic' to be good, it needs to be more than just about his coldness. It should integrate it into a well - developed story. The fanfic could start by establishing his cold nature right from the beginning, like how he keeps his distance from others. Then, as the story unfolds, it can show how this coldness is challenged. Maybe he meets someone who makes him question his cold exterior. The setting of the fanfic can also play a role. If it's set in a cold, desolate place, it can further emphasize his cold personality. And the dialogue should also reflect his coldness, with short, clipped responses that show his reserve.
Allen Walker may become a general through his unique understanding of the Innocence. His in - depth knowledge and ability to harness its power in new and innovative ways could be seen as valuable assets. This could lead to him being promoted as a general to oversee research and development related to the Innocence, as well as leading combat operations.
Some fanfictions may focus on Allen Walker's relationship with a particular vampire. For example, they could start as enemies but gradually develop a deep bond as they understand each other's motives and the difficult situations they are in.